“From human bodies and plants to industries, almost every functioning system in the world has some sort of energy storage,” he said. “If we didn’t have a stomach and fat cells and other things that provide energy storage for you, we’d be in trouble.”

Underscoring that fragility, utilities are being encouraged to add more storage to cope with grid disruptions from severe weather linked to climate change — recommendations issued in a report last month by the White House and Department of Energy.

To be successful, energy storage must displace other profitable energy infrastructure.

To lure utilities away from the existing model, the state would allow up to 50 percent ownership in storage projects within their service territories. SDG&E has lobbied for no investment limit.

“Storage represents a competing technology to the utilities that have a ‘g’ (for natural gas) in the middle of their name,” Freehling said.

Weighing options

Mike Gravely, deputy division chief for research and development at the California Energy Commission, said there is near consensus on the benefits of adding storage to the grid, mixed with a fear of the unknown.

New cost models provide some insight into how batteries may perform over time, but they cannot match today’s precise working knowledge of natural gas plants.

“If you look at the mix of solutions, everybody feels that there is a certain piece of the pie that energy storage ought to get,” said Gravely, who has worked on storage issues for two decades. “The emphasis right now is trying to find where the best opportunities lie.”

SDG&E is focused primarily on grid applications for lithium-ion batteries — the same chemistry that powers cellphones, laptop computers and electric vehicles — hoping cross-industry investments will improve costs and performance, said Lee Krevat, director of smart grid and clean transportation for SDG&E.

At Borrego Springs, the utility was able to respond to the peaks and valleys of power demands with stored energy.

“We think it’s the first time that batteries have been used to follow the (demand) load,” Krevat said. The microgrid project was funded by the Department of Energy, the California Energy Commission and SDG&E.